Nonpolar Organic Solvents Research Articles

Valorization and characterization of bio-oil from Salvadora persica seed for air pollutant adsorption.

Salvadora persica (SP) is an important medicinal plant. Numerous articles have been conducted on the leaf, the roots, and the stem of the plant, but there is little information about the seed. Thus, the present work tries to identify the chemical composition of SP seed bio-oil and investigates its use as an adsorbent for cyclohexane removal. This study extracted bio-oil from seeds using different polar and non-polar organic solvents. Two techniques have been used to determine the chemical composition of the bio-oil extracted: FTIR and GC-MS. Results show that the extracted bio-oil presented 13 new major organic bio-compounds in n-hexane and ethanol SP seed extracts. Moreover, the analytical results showed that the two extracts are complex and contained thiocyanic acid, benzene, 3-pyridine carboxaldehyde, benzyl nitrile, ethyl tridecanoate, ethyl oleate, and dodecanoic acid ethyl ester. Additionally, each technique of analysis showed that the extracted bio-oils from SP seeds are rich in non-polar compounds. Indeed, the major fatty acids obtained are pentadecylic acid, myristic acid, lauric acid, oleic acid, margaric acid, and tricosanoic acid. This work provides guidelines for identifying these compounds, among others, and offers a platform for using SP seeds as a herbal alternative for various chemical, industrial, and medical applications. Furthermore, the capacity of SP extracts for air pollution treatment, namely, the removal of cyclohexane in batch mode, was investigated. Results showed that cyclohexane adsorption could be a chemical process involving both monolayer and multilayer adsorption mechanisms. The pores and the grooves on the surface of the SP bio-oil extract helped in adsorbing the cyclohexane with an outstanding maximum removal capacity of about 674.23mg/g and 735.75mg/g, respectively, for the ethanol and hexane SP extracts, which is superior to many other recent adsorbents.

Tunable Hydrophobic Octadienyl-Ether Nanocelluloses by In Situ Ultrasonication for Reinforced Polymers and Water-Resistant Paper

One-pot syntheses and in situ ultrasonication have been optimized to generate tunable and highly hydrophobic 2,7-octadienyl-ether (ODE) cellulose nanofibrils (CNFs). Using only butadiene sulfone to serve as dual reaction medium and precursor to 1,3-butadiene (1,3-BD) for telomerization with cellulose hydroxyls, the OH-to-ODE conversion significantly improved from ca. 0.7 to 1.2, 1.8, 3.1, and 4.1 mmol of ODE/g-cellulose at 103–110 °C for 1–2 h. Ultrasonication was highly effective and versatile in the direct disintegration of ODE-cellulose (ODE-cell) in nonpolar organic solvents and plant oils into ODE-CNFs as well as pretreating cellulose for improved functionalization. Mixing 2 wt % in situ ultrasonicated 1.2 mmol of ODE/g-cell improved the modulus of polybutadiene six times and the strength of poly(styrene-b-isoprene-b-styrene) three times, whereas in situ ultrasonication of 1.8 mmol/g-cell directly with linseed oil at merely 0.07 wt % created holistic biobased hydrophobic cellulose paper to resist water penetration while also significantly improving the tensile strength. This optimized telomerization and streamlined in situ ultrasonication approach has presented a sustainable synthesis and processing strategy to generate highly hydrocarbon-compatible nanocelluloses previously unattainable.

Atmospheric Pressure Plasma-Treated Polyurethane Foam as Reusable Absorbent for Removal of Oils and Organic Solvents from Water.

This paper reports the optimization of a two-step atmospheric pressure plasma process to modify the surface properties of a polyurethane (PU) foam and, specifically, to prepare a superhydrophobic/superoleophilic absorbent for the removal of oils and nonpolar organic solvents from water. In particular, in the first step, an oxygen-containing dielectric barrier discharge (DBD) is used to induce the etching/nanotexturing of the foam surfaces; in the second step, an ethylene-containing DBD enables uniform overcoating with a low-surface-energy hydrocarbon polymer film. The combination of surface nanostructuring and low surface energy ultimately leads to simultaneous superhydrophobic and superoleophilic wetting properties. X-ray photoelectron spectroscopy, scanning electron microscopy and water contact angle measurements are used for the characterization of the samples. The plasma-treated PU foam selectively absorbs various kinds of hydrocarbon-based liquids (i.e., hydrocarbon solvents, mineral oils, motor oil, diesel and gasoline) up to 23 times its own weight, while it completely repels water. These absorption performances are maintained even after 50 absorption/desorption cycles and after immersion in hot water as well as acidic, basic and salt aqueous solutions. The plasma-treated foam can remove mineral oil while floating on the surface of mineral oil/water mixtures with a separation efficiency greater than 99%, which remains unaltered after 20 separation cycles.

Corralarenes: A Family of Conjugated Tubular Hosts.

Despite the advances in host-guest chemistry, macrocyclic hosts with deep cavities are far from abundant among the large number of wholly synthetic hosts described in the literature. Herein, we describe the design and synthesis of two new tubular hosts, namely, corral[4]arene and corral[5]arene. The former has been isolated and characterized as two conformational diastereoisomers, one is centrosymmetric and the other asymmetric. The latter, a fivefold symmetrical and flexible host, has also been investigated in detail. It is composed of five 4,4'-dimethoxybiphenyl units bridged by ethynylene linkers at their 2,2'-positions and adopts a pentagonal conformation with a tubular-shaped cavity in the presence of guests. This structure endows corral[5]arene not only with a conjugated backbone, capable of bright fluorescent emission (quantum yield, 56%), but also a deep π-electron-rich aromatic cavity with remarkable conformational flexibility. The adaptive cavity of corral[5]arene allows it to accommodate a wide range of neutral and positively charged electron-deficient guests with different molecular sizes and shapes. Binding constants between this host and these guests in three different nonpolar organic solvents lie in the range of 103 to 107 M-1. Moreover, corral[5]arene exhibits dynamic chirality on account of the axes of chirality associated with each of the five biphenyl units and displays first-order transformation as exhibited by circular dichroism in response to the addition of chiral guests. All these stereochemical features render corral[5]arene an attractive host for a variety of supramolecular and nanotechnological applications.

Dispersion corrected-DFT investigation on the adsorption and selective detection of organic solvent vapors by Cu2(HCOO)4 paddle wheel of metal organic framework

Porous metal organic frameworks (MOFs) has shown large surface area and high micropore volume making it a promising electrode material for sensing devices. Adsorption and electronic sensitivity of copper-based open metal sites paddlewheel (Cu2(HCOO)4) towards polar, moderately polar, and non-polar organic solvent vapors (OSVs) were was investigated using density functional theory, employing B3LYP. The most stable adsorption structures were those with the OSVs interacting with the metal node of PW. Based on calculations, the adsorption energy of molecules is in the range of −7.8 to −24.8 kcal/mol, −9.2 to −25.7 kcal/mol, and −6.6 to −10.9 kcal/mol for polar, moderately polar, and non-polar OSVs, respectively. Also sensing activities of PW were studied from three points of view band gap changing, sensing factor, and work function changes. From the standpoint of conductivity changing, Cu-PW has (i) low sensitivity to acetonitrile, acetone, dimethyl formamide, dimethyl ether, benzene, and ethanol; (ii) moderate sensitivity to toluene, and (iii) strong sensitivity to THF detection so that its HOMO/LUMO gap of the PW is significantly decreased from 1.63 to 0.97 eV which may increase the electrical conductivity, sensing factor is 1.4 * 1011, and work function changing is 0.45 eV after THF adsorption. Thus, we suggest that Cu-PW may be used as a highly sensitive/selective and multi-time reusable sensor material for THF detection.

A Stay-at-Home Chemistry Activity to Illustrate Intermolecular Forces

Water and an immiscible organic liquid are placed in a small plastic bottle. Ten small pieces of a notecard which is shaded on one side by crayon or pencil (graphite or colored) are cut out and placed inside the bottle. After capping and shaking, the notecard pieces float at the liquid–liquid interface with the shaded side facing the nonpolar organic solvent. This activity uses simple and easily obtained consumer materials and has been used with students from elementary school through introductory college to illustrate the concept of noncovalent (intermolecular) forces.

Fit-for-Purpose Assessment of QuEChERS LC-MS/MS Methods for Environmental Monitoring of Organotin Compounds in the Bottom Sediments of the Odra River Estuary.

Organotin compounds (OTCs) are among the most hazardous substances found in the marine environment and can be determined by either the ISO 23161 method based on extraction with non-polar organic solvents and gas chromatography analysis or by the recently developed QuEChERS method coupled to liquid chromatography-mass spectrometry (LC-MS/MS). To date, the QuEChERS LC/MS and ISO 23161 methods have not been compared in terms of their fit-for-purpose and reliability in the determination of OTCs in bottom sediments. In the case of ISO 23161, due to a large number of interferences gas chromatography-mass spectrometry was not suitable for the determination of OTCs contrary to more selective determination by gas chromatography with an atomic emission detector. Moreover, it has been found that the derivatization of OTCs to volatile compounds, which required prior gas chromatography determination, was strongly affected by the sediments’ matrices. As a result, a large amount of reagent was needed for the complete derivatization of the compounds. Contrary to ISO 23161, the QuEChERS LC-MS/MS method did not require the derivatization of OTC and is less prone to interferences. Highly volatile and toxic solvents were not used in the QuEChERS LC-MS/MS method. This makes the method more environmentally friendly according to the principles of green analytical chemistry. QuEChERS LC-MS/MS is suitable for fast and reliable environmental monitoring of OTCs in bottom sediments from the Odra River estuary. However, determination of di- and monobutyltin by the QuEChERS LC-MS/MS method was not possible due to the constraints of the chromatographic system. Hence, further development of this method is needed for monitoring di- and monobutyltin in bottom sediments.

Structure Prediction and Characterization of Thermostable Aldehyde Dehydrogenase from Newly Isolated Anoxybacillus geothermalis Strain D9.

In nature, aldehyde dehydrogenase (ALDH) is widely distributed and mainly involved in the oxidation of aldehydes. Thermostability is one of the key features for industrial enzymes. The ability of enzymes to withstand a high operating temperature offers many advantages, including enhancing productivity in industries. This study was conducted to understand the structural and biochemical features of ALDH from thermophilic bacterium, Anoxybacillus geothermalis strain D9. The 3D structure of A. geothermalis ALDH was predicted by YASARA software and composed of 24.3% β-sheet located at the center core region. The gene, which encodes 504 amino acids with a molecular weight of ~56 kDa, was cloned into pET51b(+) and expressed in E.coli Transetta (DE3). The purified A. geothermalis ALDH showed remarkable thermostability with optimum temperature at 60 °C and stable at 70 °C for 1 h. The melting point of the A. geothermalis ALDH is at 65.9 °C. Metal ions such as Fe3+ ions inhibited the enzyme activity, while Li+ and Mg2+ enhanced by 38.83% and 105.83%, respectively. Additionally, this enzyme showed tolerance to most non-polar organic solvents tested (xylene, n-dedocane, n-tetradecane, n-hexadecane) in a concentration of 25% v/v. These findings have generally improved the understanding of thermostable A. geothermalis ALDH so it can be widely used in the industry.

Nelumbo nucifera leaves as source of water-repellent wax: Extraction through polar and non-polar organic solvents

Nelumbo nucifera leaves are rich source of natural wax possessing super-hydrophobic properties. It provides protection to them from ecological turbulences and climatic wear and tear. In this study, various experiments have been conducted to observe the yield of extraction and the determination of various functional groups, which are present in natural wax, derived from Nelumbo nucifera leaves. The natural wax has been extracted from lotus leaves through non-polar (hexane) and polar (ethanol) solvent via different extraction methods. The superhydrophobic wax has been successfully extracted with hexane. Whereas, ethanol did not extract the water-repellent wax of lotus leaf. Considering the cumulative amount, i.e. (desired + undesired), the maceration shows the extraction of 2.9% (%w/w, through hexane) and 10.2% (%w/w, through ethanol), while it was found 2.5% (%w/w, cycle period 15 min) and 9.0% (%w/w, cycle period 26 min) respectively, in case of Soxhlet extraction technique. For this specific case of natural wax recovery from biomass (lotus leaf), the maceration (traditional method) resulted a little bit superior extraction yield in comparison to the Soxhlet extraction method for extraction of crude wax. In the case of non-polar solvent (hexane), an extraction yield of 1.97% (%w/w) through maceration method was observed while in the case of non-polar solvent (ethanol), an extraction yield of 1.62% (%w/w) through Soxhlet extraction was observed. The TLC analysis on both types of extracts was performed. For the detection of various hydrocarbon chains in the crude wax extracts, FTIR was also performed. Topography of wax surface and wax-coated waterproof fabric was compared through SEM.

Solution-processable microporous polymer platform for heterogenization of diverse photoredox catalysts

In contemporary organic synthesis, substances that access strongly oxidizing and/or reducing states upon irradiation have been exploited to facilitate powerful and unprecedented transformations. However, the implementation of light-driven reactions in large-scale processes remains uncommon, limited by the lack of general technologies for the immobilization, separation, and reuse of these diverse catalysts. Here, we report a new class of photoactive organic polymers that combine the flexibility of small-molecule dyes with the operational advantages and recyclability of solid-phase catalysts. The solubility of these polymers in select non-polar organic solvents supports their facile processing into a wide range of heterogeneous modalities. The active sites, embedded within porous microstructures, display elevated reactivity, further enhanced by the mobility of excited states and charged species within the polymers. The independent tunability of the physical and photochemical properties of these materials affords a convenient, generalizable platform for the metamorphosis of modern photoredox catalysts into active heterogeneous equivalents.

Conductive coatings based on concentrated silver organosols stabilized with Tergitol NP4/Aerosol OT mixture

Concentrated organosols of silver nanoparticles stabilized by a mixture of anionic AOT and nonionic Tergitol NP4 surfactants were obtained using high-performance emulsion synthesis and non-aqueous electrophoresis. The nanoparticles can be dispersed both in nonpolar organic solvents and in water with the preservation of its size and stability. The substitution of the dispersion medium from nonpolar to polar is accompanied by a significant increase in the electrokinetic potential of nanoparticles and a change in the sign of the surface charge from positive to negative. The minimum thermolysis temperature necessary for the formation of a continuous conductive film can be varied by changing in the composition of the surfactant mixture. In combination with the full wettability of both hydrophobic and hydrophilic substrates, such set of properties makes the obtained concentrates promising precursors for use in functional printing.

Synthesis of a Solid Base Catalyst Formed from Zinc(II) Acetylacetonate and Consisting of MgO Modified with ZnO

Solid base catalysts consisting of MgO modified with 10 mol% ZnO (ZnO/MgO) were prepared by depositing zinc(II) acetylacetonate (Zn(acac)2) in polar and nonpolar organic solvents on the surface of MgO and Mg(OH)2. The process was followed by thermal decomposition in air at 773 K over a period of 3 h. The activity of MgO modified with Zn(acac)2 for base-catalyzed retroaldol reaction (the decomposition of diacetone alcohol (4-hydroxy-4-methyl-2-pentanone) to acetone) at 299 K was higher than the activity of unmodified MgO prepared by thermal decomposition of Mg(OH)2. The activity of the catalysts prepared by depositing Zn(acac)2 on Mg(OH)2 was lower than that of unmodified MgO. Analysis of X-ray diffraction patterns revealed the presence of highly intense peaks, which were assigned to the ZnO units in the samples with high catalytic activity. ZnO was deposited in the form of large particles on the surface of MgO in the catalysts with high activity.

Difference in Gas-Sensing behavior of Multi-walled carbon Nanotube-Paper-Based gas sensor to polar and non-Polar organic solvents

Herein, we prepared a multi-walled carbon nanotube (MWCNT) paper by filtration, and tested its gas-sensing ability toward polar and non-polar organic solvents by comparing the magnitude of the adsorption sensitivity, response time, and reproducibility. The adsorption of non-polar organic solvents showed multilayered behavior; we presume that a stable adsorption layer is prevented from being formed owing to the measurement temperature used being higher than the critical gas temperature.

Imidazo[4,5-b]pyridine derived iminocoumarins as potential pH probes: Synthesis, spectroscopic and computational studies of their protonation equilibria

We describe the synthesis, spectroscopic characterization and computational analysis of the protonation equilibria of several newly designed imidazo[4,5-b]pyridine derived iminocoumarins to confirm their potential as pH sensing molecules in different solvents. The photophysical characterization and acid/base properties of these chromophores have been carried out in several polar and non-polar organic solvents as well as buffered aqueous solution with different pH values using UV–Vis and fluorescence spectroscopies. Obtained results revealed that both the solvent polarity and the electronic nature of substituents placed at the iminocoumarin and imidazo[4,5-b]pyridine cores significantly influence spectral responses of studied systems. An excellent agreement in experimentally measured and computationally determined pKa values and electronic excitations suggests that all systems are monoprotonated cations at neutral pH, while their transition to diprotonated forms occurs at pH values between 3.4 and 4.4, whereas they get reverted to neutral unionized molecules between 10.4 and 13.7. These small differences in narrow ranges of borderline pH values are predominantly brought about by variations in a single substituent on the iminocoumarin core, thereby allowing a simple strategy to further modify the observed sensing features and easily tune them for a specific application.

Influence of Solvent upon Reactive Capacity of Ozone in Respect of 1,3-Dimethyl-Substituted Uracils

ABSTRACT Reactive capacity of ozone in respect of three representatives of the nitrogenous bases (1,3-dimethylthymine, 1,3,6-trimethyluracil, and 5-hydroxy-1,3,6-trimethyluracil) in two solvents having different polarities (Н2О and CCl4) was investigated with the help of the ultraviolet spectroscopy method. At the first stage of investigations, coefficients of extinction of 1,3-DMU in the selected solvents were determined. At the next stage, kinetics of absorption of ozone by solutions of 1,3-dimethyl-substituted uracils at room temperature (295°K) was studied with the help of the bubbling equipment. It was established that parent compounds (О3 and 1,3-DMU) react in the equimolar relationships, that is, 1 g-mol of the consumed uracil corresponds to 1 g-mol of the absorbed ozone. On the basis of the data on the stoichiometry and kinetics of consumption of the parent compounds, obvious and definitive conclusion was made: the reactions under investigation comply with the kinetic law of the second order (of the first order – in respect of О3 and of the first order – in respect of 1,3-DMU). In the course of further investigations, temperature (from 285°K up to 309°K) dependences of constants of velocities of the second order were investigated, as well as parameters of the Arrhenius equation in respect of reactions of ozone were determined. It was established that the reaction rate constants of reactions between ozone and 1,3-DMU within the medium of the nonpolar organic solvent (CCl4) exceed the reaction rate constants within the medium of the polar solvent (Н2О).

Designing a Network of Crystalline Polymers for a Scalable, Nonfluorinated, Healable and Amphiphobic Solid Slippery Interface.

The fluorinated-liquid infused amphiphobic slippery interfaces exhibiting superior sliding of the beaded oil/water droplets, often suffer from durability and contamination issues. Here, the ability of 1) hexagonal packing of hydrocarbon sides in a selected "comb-like" polymer and 2) its reversible phase transition at 51 °C was rationally exploited to achieve temperature-assisted rapid (<1 minute) and repetitive (50 times) self-healable amphiphobic solid-slippery coating on both planar and geometrically-complex substrates. The selected "comb-like" polymer was strategically infused in a porous, hydrophilic and thick (≈4.8 μm) polymeric coating. The resultant solid and smooth interface exhibited sliding of beaded droplets of various liquids, including droplets of water, polar (ethanol, 1-propanol, 1-hexanol, DMSO, DMF), and non-polar (decane, dodecane, diiodomethane) organic solvents, edible (vegetable oil), motor, engine (petrol, diesel, kerosene) and crude oils.

Utilizing Nonpolar Organic Solvents for the Deposition of Metal-Halide Perovskite Films and the Realization of Organic Semiconductor/Perovskite Composite Photovoltaics.

Having captivated the research community with simple fabrication processes and staggering device efficiencies, perovskite-based optoelectronics are already on the way to commercialization. However, one potential obstacle to this commercialization is the almost exclusive use of toxic, highly coordinating, high boiling point solvents to make perovskite precursor inks. Herein, we demonstrate that nonpolar organic solvents, such as toluene, can be combined with butylamine to form an effective solvent for alkylammonium-based perovskites. Beyond providing broader solvent choice, our finding opens the possibility of blending perovskite inks with a wide range of previously incompatible materials, such as organic molecules, polymers, nanocrystals, and structure-directing agents. As a demonstration, using this solvent, we blend the perovskite ink with 6,6-phenyl-C-61-butyric acid methyl ester and show improved perovskite crystallization and device efficiencies. This processing route may enable a myriad of new possibilities for tuning the active layers in efficient photovoltaics, light-emitting diodes, and other semiconductor devices.

Single-Chain Mechanical Properties of Gelatin: A Single-Molecule Study.

Gelatin is an important natural biological resource with a wide range of applications in the pharmaceutical, industrial and food industries. We investigated the single-chain behaviors of gelatin by atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS), and found that gelatin exists as long chains by fitting with the M-FJC model. By comparing the single-chain elasticity in a nonpolar organic solvent (nonane) and DI water, it was surprising to find that there was almost no difference in the single-chain elasticity of gelatin in nonane and DI water. Considering the specificity of gelatin solubility and the solvent size effect of nonane molecules, when a single gelatin chain is pulled into loose nonane, dehydration does not occur due to strong binding water interactions. Gelatin chains can only interact with water molecules at high temperatures; therefore, no further interaction of single gelatin chains with water molecules occurred at the experimental temperature. This eventually led to almost no difference in the single-chain F–E curves under the two conditions. It is expected that our study will enable the deep exploration of the interaction between water molecules and gelatin and provide a theoretical basis and experimental foundation for the design of gelatin-based materials with more functionalities.

A photonic crystal material for the online detection of nonpolar hydrocarbon vapors.

A modern level of nanotechnology allows us to create conceptually new test systems for chemical analyses and to develop sensitive and compact sensors for various types of substances. However, at present, there are very few commercially available compact sensors for the determination of toxic and carcinogenic substances, such as organic solvents that are used in some construction materials. This article contains an overview of how 3D photonic crystals are used for the creation of a new test system for nonpolar organic solvents. The morphology and structural parameters of the photonic crystals, based upon a crystalline colloidal array with a sensing matrix of polydimethylsiloxane, have been determined by using scanning electron microscopy and by the results of specular reflectance spectroscopy based on the Bragg–Snell law. A new approach has been proposed for the application of this sensor in chemical analysis for the qualitative detection of saturated vapors of volatile organic compounds due to configuration changes of the photonic bandgap, recorded by diffuse reflectance spectroscopy. The exposure of the sensor to aromatic (benzene, toluene and p-xylene) and aliphatic (n-pentane, n-heptane, n-octane and n-decane) hydrocarbons has been analyzed. The reconstitution of spectral parameters of the sensor during the periodic detection of saturated vapors of toluene has been evaluated.

Emission tunable AgInS2 quantum dots synthesized via microwave method for white light-emitting diodes application

Microwave organic phase preparation of AgInS2 quantum dots (QDs) is extremely essential to the large-scale, green and efficient preparation of AgInS2 QDs. Here, commercial glycerol is used as the microwave absorber to prepare AgInS2 QDs in nonpolar organic solvent octadecene at reaction temperature range of 100–180 °C. The AgInS2 QDs can be obtained within 15 min and exhibit tunable photoluminescent properties. After decorating by ZnS layer, the prepared AgInS2@ZnS core/shell QDs emitted a bright orange-yellow light under ultraviolet light irradiation, and its quantum yield increased from 13.66% to 33.10%. Moreover, it exhibited excellent spectral tunability among the range of 608.0 nm–549.8 nm with the molar ratios of Zn/AgIn changed from 0 to 3. Finally, a WLED was fabricated by combining AgInS2@ZnS QDs and Y3Al5-xGaxO12:Ce3+ phosphors with a blue chip, the color rendering index (CRI), correlated color temperature (CCT), and luminous efficiency (LE) of the device was 87.6, 3361 K, and 58.83 lm/W, respectively, indicating the great application prospect in illumination. The research explores a novel avenue for the fast and efficient synthesis of I–III–VI semiconductor QDs in nonpolar solvent via microwave method.